YES, there is the german word for "Voice Control" appearing on the screen. So this different from the Siri screen?
Nevertheless - at least the possibility for third person to use Voice recognition should be blocked. Imagine, Voice control starts (as with the one of my iP5) to connect a third person (or a child) with a contact in a foreign country for hours! Could cost you much!
If you have time enough to do this as a third person, you could try a lot of names and contacts and if you get the connection, you know that this person has at least contact with these names.
I don´t know if you can do more with the Voice control, but I think this might be the case…

a mighty instrument for wifes: They call the secret girl friend and because your name and phone number appears on her screen she starts to talk: "Hi Darling, the last weekend was beautiful - hope your wife doesn´t know for a long time! "
Be careful, guys!